Seed layer deposition in microscale features

Abstract

A method and system for coating the interior surfaces of microscale hole features fabricated into the substantially planar surface of a work piece. The method comprises providing a work piece with a barrier metal coating that is substantially continuous and uniform both along the planar surface of the work piece and the inner surfaces of the microscale hole features wherein said barrier metal coating is applied by a substantially surface reaction limited process. The workpiece is provided with a coating, on the planar surface of the work piece, of a thick metal layer anchored to the barrier metal coat and disposed to provide substantially uniform electrical conduction capability to the microscale features located throughout and across the workpiece. An electrical contact path is provided to the electrically conductive coating at the perimeter of the work piece. The workpiece is immersed in a chemical bath, causing said chemical bath to fully contact the interior surfaces of the microscale hole features, said chemical bath containing metal ions suitable for electrodeposition. An electric potential is applied at the perimeter of the work piece to cause electrodeposition of metal ions onto all surfaces of the work piece including the interior surfaces of the microscale hole features to a predetermined finish coating in one step.

What is claimed is: 
     
       1. A method for coating and filling the interior surfaces of microscale hole features fabricated into a surface of a workpiece, the method comprising:
 providing a workpiece with a barrier metal coating that is substantially continuous along the surface of the workpiece and the interior surfaces of the microscale hole features; 
 providing a first conductive coating after the providing of the barrier metal coating, wherein the first conductive coating has a thickness of 1000 angstroms or greater on a top surface of the workpiece and wherein the first conductive coating does not substantially coat the interior surfaces of the microscale hole features; 
 providing a second conductive coating by electrodeposition, wherein the first conductive coating provides substantially uniform electrical conduction across the workpiece for electrodeposition of the second conductive coating, and wherein at least part of the second conductive coating is formed on and in contact with the first conductive coating, and further wherein the second conductive coating is deposited on interior surfaces of the microscale hole features directly on the barrier metal coating and provides a finish coating for subsequent filling of the microscale hole features; and 
 filling the microscale hole features with a conductive metal. 
 
     
     
       2. The method of  claim 1 , wherein the first conductive coating is formed by a vapor deposition process, and wherein the filling of the microscale hole features with a conductive metal is performed with an electrodeposition process. 
     
     
       3. The method of  claim 2 , wherein the first conductive coating comprises copper, the second conductive coating comprises copper, and the conductive metal filling the microscale hole features comprises copper. 
     
     
       4. The method of  claim 1 , wherein the second conductive coating is deposited by a first electrodeposition process, and wherein the microscale hole features are filled with the conductive metal by a second electrodeposition process performed subsequent to the first electrodeposition process. 
     
     
       5. The method of  claim 4 , wherein the second conductive coating provides an adherent seed layer for the subsequent filling of the microscale hole features during the second electrodeposition process.